Valve actuator



y 3, -v I N. c. 1.. BRQWN 1,958,127

VALVE ACTUATOR Original Filed Oct. 15. 1923 mww ATTORNEY Patented May 8, 1934 UNITED STATES PATENT OFFICE VALVE ACTUATOR Ned C. L. Brown,

General Railway N. Y.

668,622. Divided 1929, Serial No. 361,269

2 Claims.

This invention relates in general to means for automatically operating the brakes of a train in accordance with trackway conditions, and has more particular reference to a differential type of actuator for a usual engineers brake valve.

The present application is a division of application Ser. No. 668,622, of N. C. L. Brown, filed October 15, 1923.

In certain types of train control systems, the usual engineers brake valve is actuated automatically to apply the brakes of the train; and in order to assure the operation of this brake valve, regardless of the failure of the source of electrical energy or of circuits, the engineers valve is preferably constructed to assume its active position by the release of a certain force, rather than by the application of such a force.

Among the objects of this invention is to provide suitable pneumatically operated means for moving the usual engineers brake valve to service brake applying position in response to the release of pressure from a cylinder.

For automatically applying the brakes, it is proposed to provide a piston in a suitable cylinder which is mechanically connected to the usual engineers brake valve and is urged by main reservoir pressure of the usual air-brake system to the brake applying position, another and larger piston being provided which, under normal traffic conditions, opposes the force exerted on the first piston mentioned, and by reason of its size predominates and keeps said other piston from moving the brake valve to the brake applying position under such conditions.

Other objects, purposes, and characteristic features of the invention will appear as the description thereof progresses.

In describing the invention in detail, reference is made to the single figure of the accompanying drawing, which shows in a conventional and diagrammatic manner one embodiment of the present invention.

The brake applying apparatus includes an electro-pneumatic valve EPV having a winding 90 which is energized by a circuit controlled, as in the parent case, Ser. No. 668,622, in accordance with trackway conditions. This electro-pneumatic valve EPV comprises a chamber having partitions 92 and 93 dividing the chamber into compartments 94, 95 and 96. These partitions 92 and 93 are provided with valve seats adapted to accommodate valves 97 and 98 secured to the valve stem 99, having its upper end guided in the plug 100 and having its lower end secured to an armature 102 disposed in the magnetic shell 103 Scottsville, N. Y., assignor to Signal Company, Rochester,

1923, Serial No.

of this electro-pneumatic valve EPV, the shell 103 being closed at its lower end by a non-magnetic cap 104. On the valve stem 99 is a collar 198, between which and the partition 93 is interposed a compression coil spring 109.

The electro-pneumatic valve EPV just described is adapted to control a brake valve actuator attached to the valve casing of the usual engineers brake valve as illustrated. The particular engineers brake valve shown is of the engine and tender or E. T. type, and is provided with a valve and seat having the necessary ports to provide a release, running, holding, lap, service and emergency position as shown by the various notches. In accordance with usual practice the brake releasing position includes release, running and holding positions and the brake applying position includes service and emergency positions, while the lap position is in intermediate position. Each of the positions designated as release, running and holding is a charging position, while the non-charging positions comprise the service and emergency. This engineers brake valve E includes a valve stem 110, to which is secured the usual brake valve handle 111 and a projecting arm 112. Directly below the handle 111 and loose on the valve stem 110 is a pinion 113 meshing with a rack 114, which has its ends secured to a large piston 115 and a small piston 116, respectively. These pistons 115 and 116 are provided with the usual rings or packings and fit in cylinders 117 and 118 which are integral with, and form part of,

a housing 119 secured to the top of the usual engineers brake valve casing. The pinion 113 has therein an upstanding pin 120, which is adapted to engage the arm 112 projecting from the valve stem 110 after a predetermined arc of movement of the pinion 113 from its normal position. Thus, if the pinion 113 is rotated in a counterclockwise direction as shown, a certain amount of lost motion will take place before the pin 120 engages the arm 112 to operate the valve handle and cause an automatic application of the brakes. This lost motion is provided so that the engineer may move the handle 111 to the release position under normal conditions of the brake valve actuating mechanism without causing movement of the pin 120 by the arm 112. It will be seen that the brake valve can be automatically moved only toward and to the service position.

The small cylinder 118 is provided with a pipe 124 directly and permanently connected to main reservoir or other source of air pressure, so that air pressure of a predetermined amount is always present in this cylinder 118. The upper 1 compartment 94 of the EPV is connected to main reservoir pressure by the pipe 125; the lower compartment 96 is in communication with atmospheric pressure through the port 126; and the middle compartment 95 is connected to the large cylinder 117 of the brake valve actuator by the pipe 127.

With the electro-pneumatic valve EPV in its normal energized condition, main reservoir pressure may pass from the compartment 94 into the compartment 95 and through the pipe 127 into the large cylinder 117. Since the pressures in the cylinders 117 and 118 are the same, and since the cylinder 117 is larger than the cylinder 118, the force exerted on the piston 115 predominates over the force exerted on the piston 116, thereby maintaining the rack 114 in its extreme righthand position, as shown.

If now the circuit for energizing the winding 90 of the EPV is interrupted, the valve 97 is closed and the valve 98 is opened, so that the compartment 95 is connected to atmosphere through the compartment 96, thus releasing the pressure from the cylinder 117 and causing the rack 114 to move toward the left by reason of main reservoir pressure in the cylinder 118. This differential action of the pistons 115 and 116 is deemed to be extremely reliable, in that the force necessary to operate the engineers valve to the brake applying position is derived by main reservoir pressure which must necessarily be present when the locomotive or other railway vehicle and the train control apparatus therefor is in use. In other words, in the particular brake valve actuator shown, a certain force which can be relied upon is always present tending to cause an automatic brake application, and another and predominating force is used to maintain the brake valve actuator in its normal inactive position, so that all that is necessary to cause an automatic brake application is the release of this latter force which may be readily and reliably effected.

The above rather specific description of one form of device embodying the present invention has been given solely by way of illustration, and

is not intended, in any manner whatsoever, in a limiting sense. Obviously, this invention can 25- sume many different physical forms, and is susceptible of numerous modifications, and all such forms and modifications are included by this invention, as come within the scope of the appended claims.

Having described my invention, I now claim:-

1. A combined manual and automatic brake control device comprising, an engineers brake valve casing having a rotary valve therein for connection to an air brake system including a main reservoir, manually operable means for operating said rotary valve, and automatic means for operating said rotary valve comprising a small piston having main reservoir pressure continuously acting thereon and an opposing larger piston having the same pressure acting thereon under normal conditions, whereby a release of pressure from the larger cylinder causes an automatic application of the brakes so that the brake control device functions on the principle of failure on the side of safety.

2. A combined manual and automatic brake control device comprising, in an engineers brake valve, connectible to an air brake system including a main reservoir, a rotary valve and a handle for operating the same, an automatically controlled valve, and means for automatically operating' said rotary valve comprising a pinion operatively connected to said rotary valve, a rack engaging said pinion, a small piston on one end of said rack having main reservoir pressure acting thereon for moving said valve to the brake applying position, and a large piston opposing the force of said small piston having either main reservoir or atmospheric pressure acting thereon dependent on the position of said automatically controlled valve, whereby the rotary valve may be operated to the brake applying position by the release of main reservoir pressure from said large piston.

NED C. L. BROWN. 

